Figure 1

Proliferative responses of peripheral blood mononuclear cells (PBMCs) to heterogeneous nuclear ribonucleoprotein (hnRNP)-A2 in systemic lupus erythematosus (SLE) patients and healthy controls. Proliferation was measured by [³H]thymidine incorporation in PBMCs of 35 SLE patients and 21 controls in the presence or absence of hnRNP-A2. A stimulation index ≥3.0 and a Δcpm >1,000 cpm was considered a positive response (represented by the dashed line). The mean stimulation index (SI) was 6.7 ± 2.3 for SLE patients, and 2.3 ± 0.2 for controls (indicated by the solid bars). The difference between SLE patients and controls was highly significant (p < 0.00002). HnRNP-A2 seropositive SLE patients are indicated by crosses, and hnRNP-A2 seronegative SLE patients by diamonds.